package net.minecraft.entity.ai;

import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityCreature;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.util.EntitySelectors;

public class EntityAINearestAttackableTarget<T extends EntityLivingBase> extends EntityAITarget {
	protected final Class<T> targetClass;
	private final int targetChance;

	/** Instance of EntityAINearestAttackableTargetSorter. */
	protected final EntityAINearestAttackableTarget.Sorter theNearestAttackableTargetSorter;
	protected Predicate<? super T> targetEntitySelector;
	protected EntityLivingBase targetEntity;

	public EntityAINearestAttackableTarget(EntityCreature creature, Class<T> classTarget, boolean checkSight) {
		this(creature, classTarget, checkSight, false);
	}

	public EntityAINearestAttackableTarget(EntityCreature creature, Class<T> classTarget, boolean checkSight,
			boolean onlyNearby) {
		this(creature, classTarget, 10, checkSight, onlyNearby, (Predicate<? super T>) null);
	}

	public EntityAINearestAttackableTarget(EntityCreature creature, Class<T> classTarget, int chance,
			boolean checkSight, boolean onlyNearby, final Predicate<? super T> targetSelector) {
		super(creature, checkSight, onlyNearby);
		this.targetClass = classTarget;
		this.targetChance = chance;
		this.theNearestAttackableTargetSorter = new EntityAINearestAttackableTarget.Sorter(creature);
		this.setMutexBits(1);
		this.targetEntitySelector = new Predicate<T>() {
			public boolean apply(T p_apply_1_) {
				if (targetSelector != null && !targetSelector.apply(p_apply_1_)) {
					return false;
				} else {
					if (p_apply_1_ instanceof EntityPlayer) {
						double d0 = EntityAINearestAttackableTarget.this.getTargetDistance();

						if (p_apply_1_.isSneaking()) {
							d0 *= 0.800000011920929D;
						}

						if (p_apply_1_.isInvisible()) {
							float f = ((EntityPlayer) p_apply_1_).getArmorVisibility();

							if (f < 0.1F) {
								f = 0.1F;
							}

							d0 *= (double) (0.7F * f);
						}

						if ((double) p_apply_1_
								.getDistanceToEntity(EntityAINearestAttackableTarget.this.taskOwner) > d0) {
							return false;
						}
					}

					return EntityAINearestAttackableTarget.this.isSuitableTarget(p_apply_1_, false);
				}
			}
		};
	}

	/**
	 * Returns whether the EntityAIBase should begin execution.
	 */
	public boolean shouldExecute() {
		if (this.targetChance > 0 && this.taskOwner.getRNG().nextInt(this.targetChance) != 0) {
			return false;
		} else {
			double d0 = this.getTargetDistance();
			List<T> list = this.taskOwner.worldObj.<T>getEntitiesWithinAABB(this.targetClass,
					this.taskOwner.getEntityBoundingBox().expand(d0, 4.0D, d0),
					Predicates.<T>and(this.targetEntitySelector, EntitySelectors.NOT_SPECTATING));
			Collections.sort(list, this.theNearestAttackableTargetSorter);

			if (list.isEmpty()) {
				return false;
			} else {
				this.targetEntity = (EntityLivingBase) list.get(0);
				return true;
			}
		}
	}

	/**
	 * Execute a one shot task or start executing a continuous task
	 */
	public void startExecuting() {
		this.taskOwner.setAttackTarget(this.targetEntity);
		super.startExecuting();
	}

	public static class Sorter implements Comparator<Entity> {
		private final Entity theEntity;

		public Sorter(Entity theEntityIn) {
			this.theEntity = theEntityIn;
		}

		public int compare(Entity p_compare_1_, Entity p_compare_2_) {
			double d0 = this.theEntity.getDistanceSqToEntity(p_compare_1_);
			double d1 = this.theEntity.getDistanceSqToEntity(p_compare_2_);
			return d0 < d1 ? -1 : (d0 > d1 ? 1 : 0);
		}
	}
}
